Acid-base catalyzed modification of cellulose with hydroxyalkyl and alkoxyalkyl, epoxyalkyl sulfones



United States Patent 3,312,522 ACID-BASE CATALYZED MODIFICATION OFCELLULUSE WITH HYDROXYALKYL AND ALKOXYALKYL, EPOXYALKYL SULFONES Joe T.Adams, St. Alhans, and Herman F. Lykins, South Charleston, W. Vaassignors to Union Carbide Corporation, a corporation of New York NoDrawing. Filed July 10, 1963, Ser. No. 294,161

12 Claims. (Cl. 8120) This invention relates to a method for thetreatment of a cellulosic fabric to impart shrink resistance andwashand-wear properties thereto. In another and more particular aspect,this invention relates to a two-step method for the production ofpermanently-creased cellulosic fabrics.

It is well known that cotton and other cellulosic fabrics can be treatedwith various polyfunctional cross-linking agents, resins and the like toprovide a fabric which is wrinkle and shrink resistant and which willmaintain a crease for applications such as mens trousers, pleated skirtsand the like. However, many of these methods have been found unsuitablebecause of their lack of permanence. For example, fabrics treated withpolyhydroxy urea resins, such as dimethylol ethylene urea, are subjectto degradation under the conditions present in many commerciallaundering processes, and lose their wrinkle resistance and ability toretain -a sharp crease after only a few launderings. Other resinousmaterials, which coat the cellulosic fibers, impart an undesirable harshand boardy hand to the fabric. In addition, because the treatments ofthe prior art generally comprise the addition of the treating agent tothe fabric followed by a onestep cure, usually accomplished attemperatures employed in pressing garments made from the treated fabric,the treatment must be effected by the garment manufacturer when acreased garment is desired. Finally, because the curing occurs duringthe pressing of the garment, errors in pressing cannot be easilyrectified by repressing.

It has been found by this invention, however, that when a cellulosicfabric is impregnated with certain difunctional sulfones, as hereinafterdefined, one functional group of which reacts with cellulose under acidconditions and the other functional group of which reacts with celluloseunder basic conditions, many of the foregoing disadvantages areobviated. Because the sulfones employed in accordance with thisinvention contain no nitrogen they are not subject to degradation duringlaundering as are the nitrogen-containing resins. Because the sulfonesreact with the cellulose rather than forming a resin coating, thetreated fabric does not have a harsh and boardy hand, but rather, itretains the hand of the untreated fabric. Moreover, because the sulfonecan be permanently incorporated in the cellulosic fabric without alsocross-linking the fabric, the treatment of this invention, except forthe final cross-linking, can be conducted by the textile manufacturer.Finally, because the fabric can be pressed without also causing thefinal crosslinking, any errors in pressing can be easily rectified.

The difunctional sulfones which are employed in accordance with thisinvention have the general formula ASO B wherein A is a functional groupwhich will react with a hydroxyl group under acidic conditions (a pH ofabout 6 or less), such as a group containing a vie-epoxy the compoundsemployed in this invention have the formula RSO CH (R O),,R wherein R isa vinyl group, a fi-hydroxyalkyl group of from 2 to about 4 carbonatoms, inclusive, or a B-(alkoxy)alkyl group having from 1 to about 4carbons, inclusive, in the alkoxy group thereof and from 2 to about 4carbons, inclusive, in the alkylene group thereof; R is a divalentalkylene group of from 1 to about 3 carbons, inclusive; R is avic.-epoxyalkyl group of from2 to 8 carbons, inclusive; and n is aninteger having a value of 0 or 1. As examples of suitable difunctionalsulfones one can mention epoxyalkyl vinyl sulfones such as2,3epoxypropyl vinyl sulfone, 3,4-epoxybutyl vinyl sulfone,2,3-epoxybutyl vinyl sulfone, Z-methyl-2,3-epoxypropyl vinyl sulfone,2,3-epoxyhexyl vinyl sulfone, 5,6-epoxyhexyl vinyl sulfone and the like;(epoxy- I alkoxy) alkyl vinyl sulfones such as 2-(epoxyethoxy)ethyldroxyethyl sulfone, 2,3-epoxypropyl Z-hydroxypropyl sulgroup; and B is afunctional group which will react with a fone, 2,3-epoxy propylZ-hydroxy-l-methylpropyl sulfone, 2-(2,3-epoxypropoxy)ethylZ-hydroxyethyl sulfone and the like; and epoxyalkyl and (epoxyalkoxy)alkyl B-(alkoxy)alkyl sulfones such as 2,3-epoxypropyl 2- (methoxy)ethylsulfone, 2,3-epoxypropy1 Z-(ethoxy) ethyl sulfone, 2,3-epoxypropyl2-(butoxy)ethyl sulfone, 2-(2,3-epoxyethoxy)ethyl 2-(methoxy)ethylsulfone, and the like; et cetera. The preferred sulfones for use in thetreatment of this invention are those wherein the acidreacting group isa terminal vie-epoxy group and the base-reacting group is aB-hydroxyalkyl group because of their greater reactivity in thecross-linking treatment.

These difunctional sulfones are produced by the reaction of organicperacids with olefinically unsaturated compounds of the formula RXCH (RO) R wherein R, R and n are as defined above; R is an alkenyl radical offrom 2 to about 8 carbons, inclusive; and X is a divalent thio (S--),sulfinyl (-50-) or sulfonyl (--SO group. As examples of suitablecompounds of this type one can mention allyl vinyl sulfide, 3-butenylvinyl sulfide, crotyl vinyl sulfide, 2-hexenyl vinyl sulfide, S-hexenylvinyl sulfide, 2-(vinyloxy)ethyl vinyl sulfide, 2-(vinyloxy) propylvinyl sulfide, 2-(vinyloxy)-1-methylpropyl vinyl sulfide,2-(vinyloxy)-1-rnethylpropyl vinyl sulfide, 2-(allyloxy)ethyl vinyl-sulfide, 2-(5-hexenyloxy)ethyl vinyl sulfide, allyl 2-hydroxyethylsulfide, allyl 2-hydroxypropyl sulfide, allyl Z-hydroxy-l-methypropylsulfide, 2-(allyloxy)ethyl 2-hydroxyethyl sulfide, allyl2-(methoxy)ethyl sulfide, allyl 2-(ethoxy)ethyl sulfide, allyl2-(butoxy) ethyl sulfide, 2-(alloxy)ethyl 2-(methoxy)ethyl sulfide andthe like, as well as the corresponding sulfoxides and sulfones. Theseunsaturated precursors are readily prepared by reacting'amercaptoalcohol, for example, mercaptoethanol, with a monolefinichalide, for example allyl chloride, to produce a hydroxyalkyl alkenylsulfide, for example 2-hydroxyethyl allyl sulfide; divinyl sulfide isreacted with water to produce vinyl Z-hydroxyethyl sulfide, which isreacted with an alkenyl halide to produce a Vinyl (alkenyloxy)ethylsulfide; and the like.

The peracids which are employed to produce the sulfones are aliphatic,cycloaliphatic and aromatic peracids, including peracetic acid,perpropionic acid, perbutyric acid, perhexanoic acid, perdodecanoicacid, perbenzoic acid, monoperphthalic acid and the like. The loweraliphatic hydrocarbon peracids having from 2 to 4 carbon atoms arehighly suitable, with peracetic acid being the most preferred.

The reaction is conducted by adding a 10 to 50 weight percent,preferably 20 to 40 weight percent, solution of the peracid in a solventsuch as ethyl acetate, butyl acetate or acetone to the olefinicallyunsaturated compound at a temperature of from C. or lower to about 100C. or higher; preferably from about 25 C. to about 75 C. The amount ofperacid employed should be in excess of the stoichiometric amountrequired to oxidize the thio or sulfinyl group, if present, to thesulfonyl group, and to epoxidize the olefinic double bond. When asulfide or sulfoxide is employed as the precursor it is preferred that aportion of the peracid be added at a temperature of from about 15 C. toabout 35 C. for the oxidation of the thio or sulfinyl group to thesulfonyl group, and that the balance of the peracid be added at atemperature of from about 40 C. to about 70 C. to epoxidize the doublebond. Under these conditions the vinyl group attached to the sulfonylgroup will not epoxidize. The difunctional sulfone is separated from themixture by known techniques.

The fabric treatment of this invention essentially comprises reactingthe sulfone with the cellulosic fabric under either acidic or basicconditions to produce a presensitized fabric having properties similarto the untreated fabric. The presensitized fabric is then heated underbasic or acidic conditions to cross-link the cellulose and produce awrinkle-resistant, wash-and-wear cotton fabric.

The first step of the process of this invention consists of impregnatingthe fabric with the sulfone and curing catalyst and curing theimpregnated fabric to obtain a fabric having from about 2 to about 15,preferably from 3 to about 12, weight percent reacted difunctionalsulfone, based on the Weight of the untreated fabric. The impregnationis readily accomplished by conventional techniques wherein the fabric isimmersed in an aqueous solution of sulfone and either a basic or anacidic curing catalyst.

The concentration of the sulfone in the aqueous bath is not critical,and can vary from as low as 3 percent or less up to about 25 percent ormore. When the sulfone is present in such concentrations the desireddegree of add-on can be obtained by padding the fabricto about 100percent wet pick-up, based on the weight of the fabric, and then dryingand curing the fabric.

When an acid catalyst is employed in the first step, the reaction oncuring occurs between the epoxy group of the sulfone and a hydroxylgroup of the cellulosic fabric to provide cellulosic molecules havingpendant vinylsulfonyl, ,B-hydroxyalkylsulfonyl or fl-alkoxyalkylsulfonylgroups. This product can be represented by the general formula ZiEROH{-OR CH SO R] wherein R, R and n are as defined above; Z representsthe cellulosic fabric; and y is an integer.

The acid catalysts which are employed in effecting this reaction arelatent acid catalysts; i.e., compounds which liberate acidic componentsat temperatures of from about 100 C. to about 200 C. As examples ofsuitable latent acid catalysts one can mention Lewis acids such asstannic chloride, zinc chloride, aluminum chloride, ferric chloride andthe like; Lewis acid complexes, such as etherates and amine complexes,including piperidine-boron trifluo ride, monoethylamine-borontrifiuoride, boron trifiuoride etherates and the like; fluoroboratesalts of metals such as magnesium fluoroborate, tin fiuoroborate,cadmium 10, preferably from about 2 to about 5 Weight percent, aregenerally suitable. At low pH (3 or less), the epoxy group of thesulfone is susceptible to hydrolysis, thus reducing the efiiciency ofthe cross-linking. For this reason it is desirable to include abuifering agent in the acid bath to maintain a pH of from about 5 toabout 6. As examples of suitable buffers one can mention zinc oxide,magnesium oxide, ammonium hydroxide, zinc acetate and the like.

When a basic catalyst is employed in the first step, the reaction oncuring occurs between the vinyl, hydroxyalkyl or alkoxyalkyl group ofthe sulfone and a hydroxy group of the cellulosic fabric. The product ofthis step can be represented by the formula Z[OR SO CH (OR R wherein Z,R R n and y are as defined above and R is a divalent a,,3-alkylene groupof from 2 to 4 carbons.

The basic catalysts which are employed are strong bases such ashydroxides of sodium or potassium, or quaternary ammonium hydroxidessuch as tetramethylammonium hydroxide, benzyltrimethylammonium hydroxideand the like; or sodium or potassium salts of inorganic acids having adissociation constant of less than 5X10, such as sodium carbonate,potassium carbonate, sodium bicarbonate, potassium bicarbonate, disodiumhydrogen phosphate, dipotassium hydrogen phosphate, trisodium phos-.

phate, tripotassium phosphate and the like.

The amount of basic catalyst in the aqueous bath is not critical,provided the bath has a pH of at least about 8, and preferably at leastabout 10. In general, amounts of base of from about 1 to about 10,preferably from about 2 to about 5, weight percent are sufiicient.

The curing of the impregnated fabric is achieved by heating at fromabout 120 C. to about 200 C. If desired, the fabric can be dried atlower temperatures such as 50 C. to C. to remove the water prior tocuring. After curing the fabric, the treated fabric is then scoured toremove unreacted difunctional sulfone and curing cat alyst. The scouringis effected by washing the fabric in hot (about 170 F.) water containinga small quantity of detergent. The resulting presensitized fabric can bestored for extended periods of time or can be immediately subjected tothe final cross-linking step.

The final cross-linking is accomplis'hed'by impregnating the treatedfabric with a curing catalyst which is acidic if the catalyst employedin the first step was basic, or is basic if the catalyst in the firststep was acidic. The impregnation is accomplished in a manner similar tothat employed in the first step; i.e., padding the fabric to about 100weight percent wet pick-up in an aqueous solution containing from about1 to about 10, preferably from about 2 to about 5, weight percentdissolved catalyst. After drying, the fabric can be stored or can beimmediately heated to a temperature of from about C. to about 200 C. toeffect the final cross-linking. Because the rate of reaction, in theabsence of any catalyst, is relatively slow at temperatures of less thanabout 180 C., the fabric without catalyst can be pressed at temperaturesof'from 100 C. to 170 C. for up to five minutes without obtaining a highdegree of cross-linking. Thus, if errors are made in pressing, thegarment can be readily repressed before the final cure.

Although the first step can be either the acid-catalyzed orbase-catalyzed reaction, it is preferred to employ the acid-catalyzedstep first, particularly if the resulting presensitized fabric is to bestored for extended periods of time. If the base-catalyzed process isemployed first, the treated fabric must be thoroughly washed to ensurethat all of the catalyst, which would neutralize the latent acidcatalyst, is removed from the fabric. In addition, the pendant vinyl,alkoxy or hydroxyl groups in the treated fabric resulting from theacid-catalyzed first step are more stable than the pendant epoxidegroups resulting from a base-catalyzed first step, permitting longerstorage times of the presensitized fabric produced by the acid-catalyzedfirst step.

By the term cellulosic fabric is meant a fabric containing at least 40weight percent cellulose, including cot ton, regenerated cellulose,rayon, linen and the like.

The following examples are illustrative. In the evaluation of thetreated fabrics the following tests were employed:

A. Crease recovery-ASTM D-1295053T (warp direc tion only).

B. Wash and wear index.A sample of the fabric is washed and either spundried or tumble dried, and then evaluated as follows:

Rating: Evaluation 1 Very wrinkled. 2 Not acceptable. 3 Needs ironing. 4Wearable. 5 As ironed.

See Textile Res. 1., 26, 974 (1956) and Amer. Dye Rep, 48, 37 (1959);ASTM Method 884960.

C. Crease razing.A creased fabric was washed and the appearance of thecrease rated on a scale of from '1, indicating no crease, to 5,indicating full retention of the crease.

See 1963 Technical Manual of AATCC, page A 37, A 38, Report No. RA-61 onWash and Wear.

EXAMPLE 1 2-(2,3-ep0xypr0p0xy)ethyl Z-hydroxyethyl sulfone A mixture of345 grams of allyl chloride and 200 grams of benzene was fed dropwiseover a period of /2' hour to a solution of 312 grams of potassiumhydroxide in 1830 grams of thiodiglycol at 100 C. During this period,water of reaction was removed as an azeotrope with benzene bydistillation. The resulting mixture was heated at 100-115 C. for anadditional hours, at which time all of the water of reaction had beenremoved. After cooling to room temperature and filtering to remove thepotassium chloride formed during the reaction, the reaction mixture wasdistilled to recover 341 grams of 2-(allyloxy)ethyl 2-hydroxyethylsulfide as a fraction boiling at 9095 C. and 1.0 mm. The2-(allyloxy)ethyl Z-hydroxyethyl sulfide had a purity of 99 percent, asdetermined by analysis for olefinic unsaturation with bromine, and apurity of 94.2 percent, as determined by analysis for the hydroxyl groupwith acetic anhydride in pyridine catalyzed with perchloric acid. The2-(allyloxy)ethyl 2-hydroxyethyl sulfide had a refractive index, 11 of1.4936 and a molecular weight of 170 (theory 162) as determined by themodified Menzies-Wright method employing acetone.

To 290 grams of 2-(allyloxy)ethyl 2-hydroxyethyl sulfide there wereadded dropwise 2470 grams of a percent solution of peracetic acid inethyl acetate. Twothirds of the solution was added at C. over two hoursto oxidize the sulfide to the sulfone, at which time the mixture washeated to 5060 C. and the remainder of the solution was added over onehour to epoxidize the double bond. After heating the resulting mixtureat 50-60 C. for an additional 10 hours the mixture was fed dropwise torefluxing ethylbenzene at 50 mm. pressure, while continuously removingacetic acid as an azeotrope with the ethylbenzene. Distillation wascontinued to a kettle temperature of 60 C. at 3 mm. pressure. Thecolorless residue remaining in the kettle was 278 grams of2-(2,3-epoxypropoxy)ethyl Z-hydroxyethyl sulfone having a purity of 84%as determined by epoxide analysis using the pyridine hydrochloridemethod. The 2-(2,3- epoxypropoxy)ethyl 2-hydroxyethyl sulfone had arefractive index, n of 1.4879 and a molecular weight of 217 (theory210).

Analysis.-Calculated for C H O S: C, 39.99; H, 6.71; S, 15.2. Found: C,40.3; H, 6.6; S, 14.9.

6 EXAMPLE 2 A sample of mercerized cotton print cloth was immersed in asolution of 10 weight percent, 2-(2,3-epoxypropoxy)ethyl Z-hydroxyethylsulfone, 2.0 weight percent zinc fluoroborate and 0.3 weight percentmagnesium oxide in water, padded to about weight percent wet pick up,dried for 3 minutes at 75 C. in a forced-air oven, and

cured for 3 minutes at 150 C. The fabric was then laundered with a 0.1weight percent solution of a built detergent in water to remove residualreagents and tumble dried. The dry add-on after laundering was 5.5weight percent. The crease recovery and the wash and wear index of thetreated fabric were unchanged from the untreated fabric, being about 35percent and 1, respectively.

A portion of the treated fabric was immersed in a 5 weight percentsolution of sodium carbonate in water, padded to about 100 weightpercent wet pick-up, creased and dried on a tailors press at 96 poundssteam pressure for 5 minutes to a maximum fabric temperature of C., andthen cured for 2 minutes at 180 C. After washing and tumble drying thetreated fabric was found to have acrease recovery of 67 percent and awash and Wear index of 4.0.

EXAMPLE 3 Employing apparatus, materials and procedures similar to thosedescribed in Example 2, except that after padding with the sodiumcarbonate solution, the fabric was stored for 4 weeks at 70 F. and 65%relative humidity, and then creased and cured, there was obtained afabric having a crease recovery of 66 percent and a wash and wear indexof 4.0.

EXAMPLE 4 In a manner similar to that described in Example 2, a sampleof mercerized cotton print cloth is immersed in an aqueous solution of2,3-epoxypropyl vinyl sulfone, zinc fluoroborate and magnesium oxide,dried and cured. The treated fabric is then immersed in an aqueoussolution of sodium carbonate, dried and cured, to produce a fabrichaving good wrinkle and shrink resistance and good crease retentionproperties.

EXAMPLE 5 In a manner similar to Example 2, except that 2-(2,3-epoxypropyl)ethyl 2-(ethoxy)ethyl sulfone is substituted for the2-(2,3-epoxypr-opoxy)ethyl Z-hydr-oxyethyl sulfone, there is produced atreated cotton fabric having good wrinkle and shrink resistance and goodcrease retention properties.

. EXAMPLE 6 Twelve samples of mercerized cotton print cloth wereimmersed in .a solution of 10 weight percent 2-(2,3-epoxypropoxy)ethylZ-hydroxyethyl sulfone, 2 weight percent zinc fluoroborate, and 0.3weight percent magnesium oxide in water, padded to about 100 weightpercent wet pick-up, dried for 10 minutes at 40 C. and cured for 3minutes at C. Ten of the treated samples were immersed in a 5 weightpercent solution of sodium carbonate in water and dried for 10 minutesat 40 C. The samples were then treated as follows:

A. Two were cured for 2 minutes at C.

B. Two were stored for 4 weeks at 70 F. and 65% relative humidity andthen cured for 2 minutes at 180 C.

C. Two were creased for 5 minutes on a tailors press at 96 .pounds steampressure to a maximum fabric temperature of 140 C.

D. Two were creased for 5 minutes on a tailors press at 96 pounds steampressure to a maximum fabric temllxggature of 140 C. and then cured for2 minutes at E. Two were stored for 4 weeks at 70 F. and 65 relativehumidity, creased for 5 minutes on a tailors press at 96 pounds steampressure to a maximum fabric temlaggature of 140 C. and then cured for 2minutes at All ten samples were then washed and five samples treated byeach of the foregoing procedures were tumble dried and the other fivewere spun dried. The two samples (P) which were not subjected to thesecondary treatment with the sodium bicarbonate were washed and onesample was tumble dried and. the other was spun dried. The evaluationsof these various samples are tabulated below, together with evaluationsmade on untreated cotton samples.

We claim:

1. The method for treating a cellulosic fabric which comprisesimpregnating said fabric with an aqueous medium containing (a) a sulfoneof the formula:

wherein R is a member selected from the group consisting of vinyl,fi-hydroxyallryl of 1 to 4 carbons, and 5- (alkoxy)alkyl of 1 to 4carbons in the alkoxy group thereof and 2 to 4 carbons in the alkylenegroup thereof; R is a divalent alkylene group of from 1 to 3 carbons; Ris a vic.-epoxyalkyl group of from 2 to 8 carbons; and n is an integerhaving a value of from to 1; and (b) a curing catalyst selected from thegroup consisting of a latent acid curing catalyst and a basic curingcatalyst; and there after drying and curing said impregnated fabric.

2. The method for treating a cellulosic fabric which comprisesimpregnating said fabric with an aqueous medium having a pH of fromabout 5 to about 6 containing (a) a sulfone of the formula:

wherein R is a member selected from the group consisting of vinyl,B-hydroxyalkyl of 2 to 4 carbons, and fl-(alkoxy)alkyl of 1-to 4 carbonsin the alkoxy group thereof and 2 to 4 carbons in the alkylene groupthereof; R is a divalent alkylene group of from 1 to 3 carbons; R is aterminal-vic.-epoxyalkyl group of from 2 to 8 carbons; and n is aninteger having a value of from 0 to l, and (b) a latent 'acid curingcatalyst for the reaction of the epoxy group of said sulfone with saidfabric; and thereafter drying and curing the impregnated fabric.

3. The product produced by the process of claim 2 wherein said productcontains from 2 to weight percent reacted sulfone, based on the weightof cellulosic fabric.

4. The method for treating a cellulosic fabric which comprisesimpregnating said fabric with an aqueous medium having a pH of fromabout 5 to about 6 containing (a) a sulfone of the formula:

ROSO CH R 0 R wherein R is a member selected from the group consistingof vinyl, fi-hydroxyalkyl of 1 to 4 carbons, and B- (alkoxy)alkyl offrom 1 to 4 carbons in the alkoxy group thereof and 2 to 4 carbons inthe alkylene group thereof; R is a divalent alkylene group of from 1 to3 carbons;

R is a terminal-vie.-epoxyalkyl group of from 2 to 8 carbons; and n isan integer having a value of from 0 to l, and (b) a latent acid curingcatalyst for the reaction of the epoxy group of said sulfone with saidfabric; drying and curing the impregnated fabric; impregnating theresulting fabric with an aqueous medium having a pH of at least about 8containing a strong basic catalyst; and thereafter drying and curing theimpregnated fabric.

5. The product produced by the process of claim 4, wherein said productcontains from 2 to about 15 weight percent reacted sulfone, based on theweight of cellulosic fabric.

6. The method for treating a cellulosic fabric which comprisesimpregnating said fabric with an aqueous medium having a pH of fromabout 5 to about 6 containing (a) a 2-hydroxyalkyl2-(terrninal-vic.-epoxyalkyloxy) alkyl sulfone having from 2 to 4carbons in the hydroxyalkyl group thereof; from 4 to 12 carbons in the(epoxyalkyloxy)alkyl group thereof; and from 2 to 8 carbons in theepoxyalkyl group thereof; and (b) a latent acid curing catalyst for thereaction of said epoxyalkyl group with said cellulosic fabric; andthereafter drying and curing the impregnated fabric.

7. The method for treating a cellulosic fabric which comprisesimpregnating said fabric with an aqueous medium having a pH of fromabout 5 to 6 containing 2- hydr oxyethyl 2-(2,3-epoxypropoxy)ethyl.sulfone and a latent acid catalyst; and thereafter drying [and curingthe impregnated fabric.

8. The method for treating a cellulosic fabric which comprisesimpregnating said fabric with an aqueous medium having .a pH of fromabout 5 to about 6 containing 2-hydroxyethyl 2-(2,3-epoxypropoxy)ethylsulfone and a latent acid catalyst; drying and curing the impregnatedfabric; impregnating the resulting fabric with an aqueous medium havinga pH of at least about 8 containing a strong basic curing catalyst; andthereafter drying and curing the impregnated fabric.

9. The method for treating a cellulosic fabric which comprisesimpregnating said fabric in an aqueous medium having a pH of from about5 to about 6 containing 2-hydroxyethyl 2(2,3-epoxypropoxy)ethyl sulfoneand zinc fluoroborate; and thereafter drying and curing the impregnatedfabric.

10. The product produced by the process of claim 9, said productcontaining from 2 to 15 weight percent reacted 2-hydroxyethyl2-(2,3-epoXypropo-Xy)ethyl sulfone, based on the weight of cellulosicfabric.

11. The method for treating a cellulosic fabric which comprisesimpregnating said fabric in an aqueous medium having a pH of from about5 to about 6 containing 2- hydroxyethyl 2-(2,3-epoxypropoxy)ethylsulfone and zinc fluoroborate; drying and curing the impregnated fabric;impregnating the resulting fabric with an aqueous medium having a pH ofat least about 8 containing sodium carbonate; and thereafter drying andcuring the impregnated fabric.

12. The product produced by the process of claim 11, said productcontaining from 2 to 15 weight percent reacted Z-hydroxyethyl2-(2,3-epoxypropoxy)ethyl sulfone, based upon the weight of cellulosicfabric.

No references cited.

NORMAN G. TORCHIN, Primary Examiner.

J. CANNON Assistant Examiner.

1. THE METHOD FOR TREATING A CELLULOSIC FABRIC WHICH COMPRISESIMPREGNATING SAID FABRIC WITH AN AQUEOUS MEDIUM CONTAING (A) A SULFONEOF THE FORMULA: